Water in exhaust elbow

[Dubo]

Hi,
I was motoring back from anchoring out and after about an hour I smelled diesel exhaust coming from below. I took a quick look in the engine room and saw it was filled with smoke. I raced back to cut the engine. Once the air cleared, I saw the nipple between the exhaust elbow and the mixing elbow cracked in half (corrosion). Looking into the exhaust elbow I saw black water. My question is, what affect did the water have on the engine and once I repair the exhaust, is there anything that needs to be done beside removing the water from the exhaust? Also, how far did this water get into the engine? Before I attempt to restart the engine, do any precautions need to be considered or will the engine blow out any residual water, if any? I plan to replace the mixing elbow with a SS one along with the nipple so no issue there. Engine Yanmar 2gm20f.

Thanks for any insight as always.
Dubo

 

[JamesG161]

What engine?
My guess is NO water in engine, from your swift action.
Jim...

PS: Clean your Riser.

 

[Claude L.-Auger]

Same guess as JamesG161. Since you have a Hunter 31 I'm assuming you have the Yanmar 2GM20 engine.
As long as you were running, the exhaust gazes were probably pushing the water out through the elbow and exhaust line while also spewing fumes and possibly water through the cracked nipple. You quick action probably prevented water ingestion through the exhaust valves. Before replacing the exhaust elbow and cracked nipple, I would shut the water intake thru-hull, disconnect the hose from the skimmer to the impeller and empty it, and do the same thing to the hose from the engine water pump to the impeller. If you can empty the water off the exhaust hose to the hydrolift (muffler), it's even better. The idea is to make sure there is not water left to be ingested in the engine when attempting to re-start. Water always follows the path of least resistance and if the engine doesn't start quickly, then you risk getting some in through the exhaust valves as there is no exhaust gazes because of not starting. You could also disconnect the belt to the impeller and run the engine on the starter after decompressing the cylinders. This before putting the new elbow on. Once you're sure that the engine turns easily when decompressed and that the water has been expelled from the hoses, install the new elbow and nipple, reconnect all hoses, put belt back on impeller, bring compression levers back to normal running position, open engine water through-hull and then hit starting button. You should be good to go. Good luck

 

[Dubo]

I just wanted to thank those for the responses and relay my experience. I did replace the mixing elbow with a SS from HDI. Cost wasn't the issue but it was cheaper than OEM. After installing everything, I did as mentioned above and closed the seacock and drained the freshwater supply. I did have to crank the engine several times which told me some water did get in the exhaust manifold and who knows how far from there. Once started, there was considerable smoke at first and some oil/diesel drops in the water's exhaust. I ran the engine several minutes and it seemed to smooth out in low idle. I took it out the next day for about an hour with no real problems. When I did return, I checked the oil for any milky color and had none but the crankcase cap did have a bit of milkiness on it. Apparently some water did make it to the cylinders. As added precaution I will be changing the oil since this is saltwater.

Dubo

 

[jssailem]

@Dubo thanks for sharing the results of your challenge. Congratulations on the success.

 

[seadaddler]

I was motoring trying to catch up with some other boats when my mixing elbo
blew right off the back of engine and I was moving at top rpm’s so smoke and water
all over what a mess.
The water was the normal cooling water going out the exhaust and the threads that join the two
parts of the mixing elbo had rusted so bad it just let go
The new elbo now comes with SS double threaded part but next time I will replace with all parts
with SS mixing elbo but no problems and just replaced it running great again.
Nick

 

[JamesG161]

As added precaution I will be changing the oil since this is saltwater.

What should have happened, if you did get some salt water in the engine.

Once you restarted the engine...
1) Engine heats up contaminated oil.
2) Water evaporates and leaves the engine though the exhaust.
3) Salt crystals left behind, will be filtered out of your oil.
4) Cold engine restarts will be fast and normal.

When you change your oil filter, pour some the contents of the filter in a clear plastic container and some oil sump oil in another clear container.
Compare the samples to each other.
If the filter content oil is milky versus the sump oil...
You got some salt water in the engine.

No biggie, since you acted so swiftly
Thanks for the Thread feedback
Jim...

 

[Claude L.-Auger]

Thanks for letting us know. Good idea to change oil...and filter. Just out of curiosity, is the channel going into Jackson Creek still going almost into one house living room near R2 LOL ?